In the prior art, seats and other installation modules are fixed to mounting rails in the cabin floor, which generally run along the cabin. Other means of transport such as ships and coaches often also have such rails. In aircraft, standardised mounting rails—also referred to as seat rails are installed at a predetermined distance from one another, whereby this distance can differ from aircraft type to aircraft type. The individual rail usually comprises a light metal profile with an upwardly dovetailed cross-section, into which cylindrical and plate-shaped counterparts can be introduced from above through circular openings and the latter can also be fixed. By means of a small longitudinal displacement, the plate piece is trapped in the rail and can then be clamped or fixed. On the other hand, the guide pin, which engages into one of the rail openings, undertakes the positioning along the rail. Various installation modules can thus be installed in the cabin in a straightforward and reliable manner by means of the rails, for which purpose two neighbouring rails are as a rule used. In the case of passenger aircraft, it is mainly the passenger seats that are fixed in the rails in a large number. In order to satisfy the high demands on stability especially in the event of a crash, the seats have a stable sub-structure matched to the rail geometry. For this purpose, the fixing points of the seat sub-structure must match the spacings of the rail openings in the longitudinal direction and the spacing of the rails in the transverse direction.
In practice, the problem arises that such seat modules can often only be installed in quite specific types of aircraft, since the spacing of the rails from one another varies from aircraft type to aircraft type, even in the case of different types from the same manufacturer. This is especially disadvantageous for those who employ the aircraft, i.e. airlines, since the structure of the seat sub-structure is different even in the case of identical seat upholstery, which ultimately gives rise to a different seat type. The existing seats, therefore, often cannot be used when aircraft variants are introduced, which gives rise to unnecessary costs. A further consequence of this is that the seat manufacturer has to offer different seat types and the batch size is therefore reduced, as a result of which the production per unit becomes more expensive.
A modular seat system for aircraft is known from U.S. Pat. No. 6,659,402, wherein the seat has a primary seat structure and an integrated base plate, which is connected to the primary seat structure so as to be mechanically rotatable. The drawback with this prior art is the fact that the primary seat structure is mounted fixed and with predetermined dimensions on the base plate and consequently the actual seat is not sufficiently variable in its structural dimensions such that it can always ensure flexible installation in an aircraft.